3B Scientific UV A__B Sensor - Manual (Page 6)

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5. Operation
• Place the sensor box close to the experiment.
• Switch on the 3B NETlog TM unit and connect the
UV A/B sensor via the miniDIN cable to one of its
two analogue inputs (A or B).
• Wait for the sensor box to be detected
automatically.
• Select the appropriate measurement range for
the expected UV intensity depending on the light
source [e.g., sunlight, UV light for tanning (sun-
beds, solaria) or UV disco lights].
• Read the value of the light intensity from the
display of the 3B NETlog
TM unit.
• If the measurement range is exceeded, change
to the next higher range.
• For transmission measurements, hold the
absorber specimen between the light source and
the sensor and calculate the ratio of the
radiation intensity readings with and without
the absorber (the transmission coefficient).
6. Applications
Measuring the UV intensity during the course of a
whole day and investigating its dependence on the
time of year.
Measuring the UV transmittance (transmission
coefficient) of different glass and plastic lenses in
sunglasses and normal spectacles.
Comparing the UV transmittance of the windscreen
and side windows of a car with regard to possible
tanning or sunburn of occupants.
Does wet clothing give better protection from UV
radiation than dry clothing?
Quantitative comparison of the radiation protection
factors of sun-creams.
7. Sample experiment
Measurements of the UV transmittance
(transmission coefficient) of different glass and
plastic materials in sunglasses and normal
spectacles
Equipment required:
1 3B NETlog TM U11300
1 3B NETlab TM U11310
1 UV A/B sensor U11369
Several different pairs of sunglasses and normal
spectacles
Recommendation: Perform the experiment outdoors
on a sunny day.
• Switch on the 3B NETlog TM unit and wait for the
sensor box to be detected automatically.
• Select the 700 W/m 2 measurement range on the
sensor box.
• Select the program (template) “Ultraviolet
radiation” on the 3B NETlog
TM unit.
• Hold the UV A/B sensor in sunlight, without the
aperture cover and without the UVA filter, and
start the program.
• Choose the “Manual input” mode and record the
first of two intensity measurements.
• Hold one lens of the sunglasses in front of the
UV A/B sensor at a distance of about 10 cm.
• Now make the second intensity measurement.
• Make a graph of the two measurements to show
the effect of the lens (Fig. 3).
• If possible, repeat the experiment with another
pair of sunglasses.
Fig. 1 Spectral sensitivity characteristic of UV diode